The following descriptions and examples are not admitted to be prior art by virtue of their inclusion within this section.
Implementations of various technologies described herein generally relate to seismic acquisition. In a seismic survey, a source may be activated to generate energy, which may be reflected back by the earth's sub-surface layers. The resultant seismic wavefield may be sampled by an array of seismic receivers disposed at a distance from the seismic source. Each receiver may be configured to acquire seismic data, which are normally in the form of a record or trace representing the value of some characteristic of the seismic wavefield against time. Information about the earth's sub-surface can be obtained from the acquired seismic data.
Typically, a plurality of sources and receivers are arranged in a grid, such that the recorded data from the wavefields may substantially cover the entire area of exploration and with sufficient resolution to detect the variation of the sub-surface structure over small spatial distances. The wavefields recorded by the receivers may be a result of the superposition of many waves having different paths through the earth's sub-surface before finally reaching the receivers. This makes the reconstruction of the earth sub-surface difficult. One objective of seismic data processing is to separate the wavefields into coherent waves in connection with creating an accurate image of the earth's sub-surface layers. Because seismic data acquisition is very expensive, it is desirable to increase the distance between the grid points and still provide sufficient resolution or use the same or tighter grid and achieve finer resolution.
In a time-lapse seismic survey, a survey may be performed in the same location as a previous survey for the purpose of comparing the sub-surface structure interpretations of the two surveys. For optimal results, it may be desirable for the sources to be activated at the same locations and the receivers to be located at the same locations in both surveys. This precision may be very difficult. Therefore, a method or system designed to minimize the detrimental effects of inaccuracies in positioning the sources and receivers may be very desirable.